How to Measure for a Kitchen Sink, Explained
Measuring for a Kitchen Sink sounds easier than it actually is.
If you need the short answer here it is: The sink needs to be 3" smaller than the cabinet. If you want to know why, keep reading. The information below will be a fairly in depth, touching on aspects of installation and fitment.
Let's first cover the elements involved in the fitment of a sink into a cabinet.
First, Sink Base Sizing
Sink Bases, and most base cabinets, typically measure 24" front to back and in inch intervals in the left to right size. In other words, its exterior size. A common starting size for a sink base is the infamous 24" cabinet. I am calling it infamous because finding the biggest sink for the 24 inch cabinet is one of the most often asked question (Here is a blog dedicated to it)
Next is a 27" cabinet, then 30", 33", and 36" sink base cabinet. They do get larger, but this is less frequent. Why are there so many sizes? It all depends on the kitchen space, needs of the client, needs of the design, and budget of the renovation.
For example, if you have a 135" wall to fill with cabinets. You might have the following from left to right: 36" Drawer Base, 30" Base, 27" Sink Base. 18" double pull out trash, 24" Drawer Base.
The 27" will allow you to put a sink like this inside: Kraus 25"
What if this does not make you happy, and you want a larger sink like this: 27 "Kraus Workstation. You need to gain three inches in your sink base to accommodate the increase in sink size. To gain that space, you will have to sacrifice 3" from another cabinet. Your 18" double trash could become a 15" single, or you might swap the 36" drawer base for a 33". Regardless, cabinet layout can change.
Next, Sink Sizing for Undermount Sinks
This is where it gets more confusing.
All sinks are described in their overall size; just like the cabinets they go into.
A 27" sink is one that is 27" left to right at the mounting flanges. The basin itself is 25" Generally speaking for under mount sinks, the basin will be 2" smaller than its described size. For example, a common 23" sink will also measure 18" front to back. The bowl will be approximately 21" x 16". Check this model out: Nantucket 23"
Stay with me - It is all going to come together and make sense. I promise.
Next, Sink Fitment to the Cabinet.
Sink manufacturers will always recommend a cabinet that is a full 3" larger than the sink. Why? There is a few reasons:
1. Going back to the first section, cabinet size is the overall left to right. However the sink is going inside the cabinet walls, so we need to accommodate to wall thickness. Typically the cabinet walls will be 3/4", so a 24" cabinet will have 22.5" inside.
2. Mounting Clips - These are needed to secure the sink directly to the counter top. Every undermount sink we sell has them included in the package. The clips have a few components: The anchor, clip, and screw. The anchor is drilled into the underside of the counter top. It the receiving side of the screw. Once the anchors are secured the sink is held in place from its flange tight to the underside of the counter top. These clips are the reason why sink companies want a sink 3" smaller than the cabinet. They want room for clips on the right and left side.
We like to challenge this: Why can't the clips be mounted on the front and back of the sink flanges?
|Standard Sink Clips|
Why such variation? Not sure, but I heard that following the three inch rule gives the client and fabricator the ability to remove the sink after install, if need be.
Last note about sink clips - USE THEM. We often get contacted about information on how to re-mount a sink that fell into the cabinet from the counter top. This happens when the clips are not used, and the sink is glued in with silicone. The worst part of that situation, is that this will tend to happen when the sink is the heaviest; like when it is filled with water.
What about allowing space for my faucet? How much room do I need to mount the faucet?
As mentioned before, the standard base cabinet is 24" deep. With counter top installed, your finished kitchen bases will typically be 25"
Faucet hole requirements are 1 3/8" - 1 1/2". The faucet body will be about 2". (Sometimes more)
A sink that is 18" at the flange front to back, will leave about 5" inside the cabinet (Accounting for front and rear cabinet wall thickness). Normally the fabricator will mount the sink toward the front of the cabinet. Under most circumstances, you have plenty of room to mount a faucet. Some sinks, like this model, are even larger at 19".
Keep in mind, if you have a window ledge behind the sink, the ledge may impact the space available. The window ledge may project toward you. When pushing the limit of sink sizing, if you have a window ledge projection to account for, you will most likely be forced to select a faucet with either a "Forward Only" handle movement, or a faucet with a center handle control at the top. Now if you select a single handle faucet you need to account for the front to back movement of the temperature control. Ideally, even without the possible window ledge it is ergonomically beneficial to have a temperature control that is "forward only". Take a look at the images.
Single Hole Faucet with a centered handle | Kraus KPF-2252
Forward only handle - Saves space with less reaching
What about measuring a cabinet for an Apron Front or Farm Sink?
We follow the same 3" rule. The sink should be 3" smaller than the cabinet; a 33" apron sink needs a 36" sink base. A 30" apron sink, needs a 33" cabinet.
Regarding apron sinks, there are other elements that can allow you to push past this restriction. Conversely, there are elements that may force you to adhere to it. Allow me to explain further.
Apron Sinks require a different cabinet compared to a standard undermount sink. Furthermore, installing an apron sink, and a counter top is also different.
Take a look at these two cabinets:
The cabinet on the left is made for an apron sink. This is called a country sinkbase cabinet. Note the shorter doors. The space taken from the height of the doors is given to the space occupied by the height of the apron sink face,
The cabinet on the right is a standard sink base. Note the taller doors and panel at the top, known as a false drawer front.
The absolute largest sink you can put in a cabinet for an apron sink is the same size as the cabinet if and only if, several different factors are met. This max size of sink to a cabinet is known as "Stacking". The sink is stacked on the cabinet, and sitting on the walls, (along with additional supports)These are rarely met, and this is why the 3" rule is important.
These determining factors are:
- The placement of the cabinet in relationship to the dishwasher.
- Material of the sink. For example, fireclay sinks can be marginally larger or smaller than the intended size. This is a direct result of how fireclay sinks are made. Stainless sinks are more exact and consistent.
- What cabinets are actually next to the sink base; drawer base, corner base, or standard base.
The ultimate determining factor will be on the person installing it. If your installer or kitchen designer has the kitchen laid out where you can stack the apron sink on the cabinet, then you are in luck. If this is what you really want to achieve, make sure your cabinet installer and designer knows this before they design everything. Note- Depending on the sink, they may not be able to do this easily. Also keep in mind that the cabinet may need to be flanked by columns, fillers, or something else just so you can stack the sink. This will equate to higher costs to you, but if its the look you want, you want what you want. Right?
What if you want an apron sink in a standard sink base?
You are in luck! This transition from having an undermount sink to an apron sink is when you are keeping the cabinets you have and are getting new counter tops. The type of sinks these are called are "Retrofit Apron Front" sinks. With these sinks, the apron is a reduced height and is made to fit over the space occupied by the false drawer front. These sinks still follow the 3" rule, but do have different apron heights to work with different cabinet construction and false drawer height.
How do you measure a sink for a corner sink base?
-This pertains to the common 36" corner sink base-
The easy answer is that it is treated like a 24" cabinet. If a 21" sink is in the corner sink base, all mounting flanges are easily accessible. You can also normally easily use a 23" sink as well. Check out this page for more detail: Corner Base Sinks.